CN110892792A

CN110892792A - System and method for parallel hybrid horticulture system

Info

Publication number: CN110892792A
Application number: CN201880038137.2A
Authority: CN
Inventors: D.杨; R.约翰逊
Original assignee: Magic Bioengineering
Current assignee: Magic Bioengineering
Priority date: 2017-06-07
Filing date: 2018-02-28
Publication date: 2020-03-17
Anticipated expiration: 2038-02-28
Also published as: EP3636046A1; CA3066197A1; US20180359834A1; CN110892792B; JP7062697B2; EP3636046A4; US10264648B2; JP2020523741A; WO2018226279A1

Abstract

Examples of the present disclosure relate to systems and methods for parallel hybrid horticulture systems. More particularly, embodiments disclose utilizing a Constant Power (CP) power supply configured to operate in both a constant voltage mode and a constant current mode, wherein a maximum current state and a maximum voltage state may be programmed.

Description

System and method for parallel hybrid horticulture system

Cross Reference to Related Applications

The present application claims priority from provisional application No.62/516,462 filed 2017, 6, 7 and is a continuation of US patent US 15/692,540 filed 2017, 8, 31, 35 u.s.c § 119, which applications and patents are incorporated herein by reference in their entirety.

Background information.

Technical Field

Examples of the present disclosure relate to systems and methods for parallel hybrid horticulture systems. More particularly, embodiments disclose utilizing a Constant Power (CP) power supply configured to operate in a constant voltage or constant current mode, wherein a maximum current state and a maximum voltage state may be programmed based on characteristics of the LED strip.

Background

Conventional LEDs emit light by converting electrons into photons. As the electron velocity (current) increases, the number of emitted photons (radiant flux) increases proportionally. Since LEDs (electron to photon conversion) are not 100% efficient, the heat increases proportionally with the increase in current. At extreme currents, the quantum wells associated with the LEDs may reach saturation, and thus higher currents result in less light output. The IV curve of the LED allows a direct correlation between the voltage and the current through the LED. Based on the IV curve, the LED is sensitive to overvoltage conditions. In an over-voltage condition, the voltage in the circuit is raised above its design upper limit.

Because voltage is a function of current, voltage rises above design limits and thus pushes the current through the LED above design limits. Overvoltage conditions created by voltage surges that exceed the voltage rating of the electrical equipment can cause considerable damage to the electrical equipment. For example, when an over-voltage/over-current occurs, the LED may stop operating due to breakage in the circuit (bond wire breakage, trace burn-out) and overheating (material properties change with changes in heat).

Conventionally, a luminaire includes a plurality of LED strings coupled in parallel with a Constant Current (CC) power supply. With CC power, current is evenly distributed to each of the LED strings based on the forward voltage of the LED strings. Since the forward voltages of the LED strings are uniform, the current applied to each LED string is uniform.

However, if the number of LED strings coupled to the CC power supply falls below a given threshold, such as to a single LED string, all current from the CC power supply flows through the single LED string. This can cause the individual LED strings to be overdriven, overheat, and fail prematurely.

Accordingly, there is a need for more efficient and effective systems and methods for parallel hybrid horticulture systems that utilize constant current and/or constant power sources.

Disclosure of Invention

Examples of the present disclosure relate to systems and methods for parallel hybrid horticulture systems. More particularly, embodiments disclose utilizing a Constant Power (CP) power supply configured to operate in both a constant voltage mode or a constant current mode, wherein a maximum current state and a maximum voltage state may be programmed based on a forward voltage of the LED string. In an embodiment, the constant current set point and the constant voltage set point may be determined accordingly based on the forward voltage and the forward current across each LED string.

The first embodiment may include a constant voltage power supply coupled to a plurality of LED circuits positioned in parallel. The LED circuit may include a plurality of LEDs and a Constant Current (CC) driver connected in series. In response to an increase or decrease in the number of LED circuits positioned in parallel, the constant current driver may maintain a constant current applied to the corresponding LED circuit.

The second embodiment may include a constant voltage power supply coupled to a plurality of LED circuits positioned in parallel. The LED circuit may include a resistor and a LED string positioned in series, wherein a plurality of LED circuits are positioned in parallel with each other. The resistors within the LED circuits may be configured to limit the current applied to the corresponding LED circuit. In an embodiment, the size of the resistor controls the current flowing through the plurality of LED circuits in series. In an embodiment, each resistor in the LED circuit may have the same and/or similar size.

The third embodiment may include a constant power supply coupled to the plurality of LED strings. The constant power supply may be configured to first operate in a Constant Current (CC) mode and switch to a Constant Voltage (CV) mode when in overvoltage protection. In this embodiment, the forward voltage of the LED string may be configured to be lower than the maximum design output forward voltage, and the constant power supply may initially operate in a constant current mode. In response to a decrease in the number of LED strings, current may flow through the LED strings until an overvoltage condition is reached based on the output forward voltage of the LED strings. When the overvoltage condition is satisfied, the power supply may not allow additional current to flow through the LED string, and the power supply may switch to a constant voltage mode. Because the IV curves of the LED strings are consistent, the over-current limits of the LED strings can be customized based on the characteristics of the LED strings.

Embodiments may be configured to simplify the construction of LED strips by having fewer components, higher reliability due to a lower number of components and connections between fewer components that may fail. Additionally, costs associated with labor, development, materials, and quality control may be reduced.

These and other aspects of the invention will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. While the following description indicates various embodiments of the present invention and numerous specific details thereof, the following description is given by way of illustration and not of limitation. Many substitutions, modifications, additions or rearrangements may be made within the scope of the invention, and the invention includes all such substitutions, modifications, additions or rearrangements.

Drawings

Non-limiting and non-exclusive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.

Fig. 1 depicts a parallel hybrid power horticulture system, according to an embodiment;

fig. 2 depicts a gardening system according to an embodiment;

fig. 3 depicts a gardening system according to an embodiment;

fig. 4 depicts a horticulture system wherein the number of LED circuits is reduced below a threshold number, according to an embodiment;

fig. 5 depicts a gardening system according to an embodiment;

fig. 6 depicts a gardening system according to an embodiment;

fig. 7 depicts a horticulture system wherein the number of LED circuits is reduced below a threshold number, according to an embodiment;

FIG. 8 depicts a graph plotting a maximum current set point based on a maximum voltage associated with a representative LED in accordance with an embodiment;

fig. 9 illustrates a method for minimizing an overdrive state using a constant power supply configured to operate in a constant current or constant power mode according to an embodiment.

Corresponding reference characters indicate corresponding components throughout the several views of the drawings. Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of various embodiments of the present disclosure. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present disclosure.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present embodiments. It should be apparent, however, to one skilled in the art that the specific details need not be employed to practice the present embodiments. In other instances, well-known materials or methods have not been described in detail in order to avoid obscuring the present embodiments.

Fig. 1 depicts a parallel hybrid power horticulture system 100, according to an embodiment. As depicted in fig. 1, the horticulture system 100 may include a CV power supply 110 and an LED circuit 120, the LED circuit 120 including a CC driver 130 and an LED 140.

CV power supply 110 may be a power supply configured to output a fixed and/or constant voltage. The CV power supply 110 may be configured to have a varying current based on the load caused by the LEDs 140 and the LED circuit 120. The fixed voltage associated with the CV power supply 110 may be set based on the forward voltage and the load created by the LED circuit 120.

The LED circuits 120 may be coupled in parallel with each other and with the CV power supply 120. Each LED circuit 120 may include a corresponding CC driver 130 and a plurality of LEDs 140 positioned in series. The plurality of LEDs 140 may be the same and/or different LEDs.

The CC driver 130 may be an electrical device configured to output a constant current. The CC driver 130 may be configured to prevent the LED140 from having a high current level that causes the LED140 to malfunction. The fixed current associated with the CC driver 130 may be set based on the desired load of the LED circuit.

The LED140 may be a light emitting diode that emits light when activated. When a suitable voltage is applied to the LED140, electrons associated with the LED release energy in the form of photons. Each of the LEDs 140 may have a forward voltage required for the LED to operate and create a load for the horticulture system 100.

Fig. 2 depicts a gardening system 100 according to an embodiment. As depicted in fig. 2, the gardening system 100 may have a number (one) of LED circuits 120 that is below the light string threshold. The number of LED circuits 120 may be reduced for various reasons, such as failure of the LED circuit, removal of the LED circuit, and the like. In embodiments with a CC driver, the current load drawn from CV power supply 110 may be based on what is needed by LEDs 140. The CC driver 130 may be configured to protect the circuit and will not allow the LED140 to be overdriven.

In an embodiment, the CV power supply 110 may be configured to apply a constant voltage to the single or remaining LED circuit(s) 120, while the CC driver 130 may be configured to drive the LEDs 140 at a constant current. Thus, the LED140 may not have a higher voltage than the power threshold to activate the LED140 and may always have a desired current that will not overdrive the LED 140.

Fig. 3 depicts a gardening system 300 according to an embodiment. Some of the elements depicted in system 300 may be described above. Additional description of these elements is omitted for the sake of brevity.

As depicted in fig. 3, a plurality of LED circuits 310 may be positioned in parallel with one another. Each of the LED circuits 310 includes a resistor 320 and an LED string 140. The resistor 320 may be configured to limit and control the current applied to each of the LED strings 140. As the number of LED circuits 310 increases or decreases, the CV power supply 110 may dynamically change the current through the system 300. In an embodiment, the string voltage across each LED string 140 may substantially match the fixed voltage supplied by the CV power supply 110. Thus, the size of the resistor 320 may be kept relatively small while having a high efficiency.

As depicted in fig. 4, the number of LED circuits 310 within the gardening system 300 may be reduced below a threshold number. However, the resistor 320 may be configured to limit the current applied to the individual LED circuits 310. In an embodiment, the resistor 320 may be set at a size at which the remaining LED strings 140 may not be in an overdriven state, even when the number of LED circuits 310 within the system 100 is below a threshold number.

Fig. 5 depicts a gardening system 500 according to an embodiment. Some of the elements depicted in system 500 may be described above. Further description of these items is omitted for the sake of brevity.

As depicted in fig. 5, a Pulse Width Modulator (PWM) 510 may be configured to be positioned between the CV power supply 110 and the resistor 320. The PWM 510 may be configured to control and create a square wave of a given frequency and duration. These square waves can be used as signals that can be turned off and on, or those with high and low signals. In an embodiment, the PWM 510 may vary the frequency and duty cycle of the wave, where the frequency may be a faster time period, such as 2 milliseconds, than the human eye can discern the difference. By altering the frequency of the signal and the time (duty cycle) that the signal is in the off and/or on position, the LED string 140 can appear to be dimmed by the chopped voltage signal. This may be based on the ratio between the high and low signals when the LED is illuminated.

In an embodiment, PWM 510 may be configured to limit the amount of time CV power supply 110 applies a constant voltage to resistor 320. By controlling the length of time that the LED string 140 receives power, the LED string 140 may appear to be dimmed. For example, if the square wave is in the on position for fifty percent of the time and in the off position for fifty percent of the time, the LED string 140 may appear to be dimmed by fifty percent. Alternatively, if the square wave is in the on position for seventy percent of the time and in the off position for thirty percent of the time, the LED string 140 may appear to be dimmed by thirty percent. To cause the LED string 140 to become more or less dimmed, the ratio of the amount of time that the wave supplied by the PWM 510 is in the off or on position may be increased or decreased accordingly.

In an embodiment, the PWM 510 may be configured to operate with a constant power supply when the constant power supply operates in a constant voltage or constant current mode.

Fig. 6 depicts a gardening system 600 according to an embodiment. Certain elements depicted in system 600 may be described above. Additional description of these elements is omitted for the sake of brevity. The system 600 may include a Constant Power (CP) power supply 610 and an LED string 620.

CP power supply 610 may be a power supply configured to operate in both Constant Voltage (CV) mode and Constant Current (CC) mode, with both the CV mode and the CC mode having over-current and over-voltage protection. In an embodiment, the forward voltage of CP power supply 610 may be slightly higher than the forward voltage of LED string 620, such that CP power supply 610 initially operates in CC mode.

As depicted in fig. 7, the number of LED strings 620 within the horticulture system 600 may be reduced below a threshold number. By varying the number of LED strings 620, the load of CP power supply 600 can be dynamically varied. In response to a decrease in the number of LED strings 620 within the system 600, the CP power supply 610 may supply power to the remaining LED strings 620 with a given current until the LED strings 620 are in an overvoltage condition. At this point, the power supply may not allow additional current to flow through the remaining LED strings 620. CP power supply 610 may switch mode to constant voltage mode due to an increase in the voltage supplied by CP power supply 610.

When in constant voltage mode, the supplied voltage from CP power supply 610 may be programmed to a smaller amount compared to the overvoltage condition of LED string 620. However, because the load on the system 100 is reduced when the number of LED strings 620 is below the threshold, the floating current supplied by the CP power supply 610 in the constant voltage mode may be kept lower compared to the overcurrent state.

Fig. 8 depicts a graph 800 plotting a maximum current set point 810 based on a maximum voltage 812 associated with a representative LED. The series LED string 620 multiplies the voltage by the number of LEDs. In an embodiment, while CP power supply 610 is providing a constant current, in response to limiting the number of LED strings 620 in system 600, the voltage applied to the lesser number of LED strings 620 remaining in system 600 may be increased. However, when if the remaining LED string 620 is in an overvoltage condition, the increase in voltage may stop, wherein the CP power supply may change to be in constant voltage mode.

Additionally, the graph 800 depicts a constant current set point 820 that is adjustable by the maximum current output 810. The constant current set point 820 may be based on the maximum voltage 812 of the LED string 620, where the current associated with the constant current set point 820 may be less than the current associated with the maximum current set point 810. By being able to program the CP power supply 610 and set the maximum current and maximum voltage states of the LED string 620 based on the characteristics 830 of the LED string, finer adjustments of the drive current and maximum light bar current can be applied to the system 600.

Fig. 9 illustrates a method 900 for minimizing an overdrive condition using a constant power supply configured to operate in a constant current or constant power mode, according to an embodiment. The operations of method 900 presented below are for illustrative purposes. In some embodiments, method 900 may be accomplished with one or more additional operations not described and/or without one or more of the operations discussed. Additionally, the order in which the method 900 is illustrated in fig. 9 and described below is not intended to be limiting.

At operation 910, the constant power supply may be configured to operate in a constant current mode in which constant power is supplied to the plurality of LED strings at a dynamic voltage based on a load of the plurality of LED strings.

At operation 920, the number of LED strings may be reduced, which may correspondingly change the load. This may cause the voltage supplied to the LED string to increase.

At operation 930, the voltage supplied by the constant power supply may be increased until a preprogrammed amount is reached. The pre-programmed amount may be based on an over-voltage condition of the LED string.

At operation 940, the constant power supply may dynamically and automatically change from a constant current mode to a constant voltage mode in response to the voltage being greater than or equal to a preprogrammed amount.

At operation 950, the constant power supply may supply a smaller voltage to the remaining LED strings than the overvoltage state of the LED strings by having a floating current. The constant power supply can be dynamically restored to constant current mode if the floating current associated with the constant power supply becomes higher compared to the pre-programmed amount of current.

Although the technology has been described in detail for the purpose of illustration based on what is currently considered to be the most practical and preferred implementations, it is to be understood that such detail is solely for that purpose and that the technology is not limited to the disclosed implementations, but, on the contrary, is intended to cover modifications and equivalent arrangements that are within the spirit and scope of the appended claims. For example, it is to be understood that the present technology contemplates that, to the extent possible, one or more features of any implementation can be combined with one or more features of any other implementation.

Reference throughout this specification to "one embodiment," "an embodiment," "one example," or "an example" means that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment," "in an embodiment," "one example" or "an example" in various places throughout this specification are not necessarily all referring to the same embodiment or example. Furthermore, the particular features, structures, or characteristics may be combined in any suitable combination and/or sub-combination in one or more embodiments or examples. Additionally, it should be appreciated that the figures provided herewith are for explanation purposes to persons of ordinary skill in the art and that the drawings are not necessarily drawn to scale.

The flowchart and block diagrams in the flowchart illustrations illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems which perform the specified functions or acts, or combinations of special purpose hardware and computer instructions.

Claims

1. A hybrid gardening system comprising:

a plurality of light emitting diode strings positioned in parallel with one another, wherein the plurality of light emitting diode strings comprises a plurality of light emitting diodes;

a constant power supply configured to operate in a constant voltage mode or a constant current mode for a given period of time, wherein the constant power supply is configured to supply power to the plurality of light emitting diode strings.

2. The hybrid horticulture system of claim 1, wherein the constant power source has a predetermined set maximum voltage, the predetermined set maximum voltage.

3. The hybrid horticulture system of claim 2, wherein constant power source is configured to switch from a constant current mode to a constant voltage mode in response to a supply voltage from said constant power source being greater than a predetermined LED string voltage.

4. The hybrid horticulture system of claim 3, wherein the constant power source is preprogrammed with a constant current set point, wherein a first current level associated with said constant current set point is less than a second current level associated with a maximum current set point.

5. The hybrid horticulture system of claim 4, wherein a maximum current set point is associated with a predetermined set maximum voltage.

6. The hybrid horticulture system of claim 4, wherein the constant power source supplies current at a constant current set point in a constant current mode.

7. The hybrid horticulture system of claim 1, further comprising:

a pulse width modulator positioned between the constant power source and the plurality of light bar strings.

8. The system of claim 7, wherein the pulse width modulator is configured to control and create a square wave of a given frequency and duration that alternates between a high signal and a low signal, wherein the frequency is faster than 2 milliseconds.

9. The system of claim 8, wherein the plurality of light emitting diodes within the plurality of light emitting diode strings appear to dim based on a ratio between an amount of time between a high signal and a low signal.

10. The system of claim 1, wherein the constant power supply is initially set to a constant current mode.

11. A method for a hybrid horticulture system, comprising:

positioning a plurality of light emitting diode strings in parallel with each other, wherein the plurality of light emitting diode strings comprises a plurality of light emitting diodes;

supplying power to the plurality of light emitting diode strings via a constant power supply; the constant power supply is configured to operate in either a constant voltage mode or a constant current mode for a given period of time.

12. The method of claim 11, further comprising:

when a constant power supply operates in a constant current mode, a predetermined set maximum voltage is set for the constant power supply, the predetermined set maximum voltage being associated with an overvoltage condition of a plurality of light emitting diode strings.

13. The method of claim 12, further comprising:

switching a constant power supply from a constant current mode to a constant voltage mode in response to a supply voltage from the constant power supply being greater than a predetermined set maximum voltage.

14. The method of claim 13, further comprising:

the constant power source is pre-programmed to have a constant current set point, wherein a first current level associated with the constant current set point is less than a second current level associated with a maximum current set point.

15. The method of claim 14, wherein the maximum current set point is associated with a predetermined set maximum voltage.

16. The method of claim 14, wherein the constant power supply supplies current in a constant current mode at a constant current set point.

17. The method of claim 11, further comprising:

positioning a pulse width modulator between a constant power source and a plurality of light bar strings, wherein the pulse width modulator is configured to operate when the constant power source operates in a constant voltage mode.

18. The method of claim 17, further comprising:

generating a square wave having a given frequency and duration via the pulse width modulator, the square wave alternating between a high signal and a low signal, wherein the frequency is faster than 2 milliseconds.

19. The method of claim 18, further comprising:

dimming a plurality of light emitting diodes within a plurality of light emitting diode strings based on a ratio between an amount of time between a high signal and a low signal.

20. The method of claim 11, further comprising:

the constant power supply is initially set to a constant current mode.